In recent years, due to the rapid development of traffic and transportation, the traffic volume and vehicle axle load rapidly increase and the travelling, is channelized, which raises higher requirements for the performance of asphalt and asphalt mixture. On the one hand, the asphalt mixture is required to have high-temperature stability, thus not causing rutting; on the other hand, the asphalt is required to have low-temperature crack resistance and fatigue resistance, and prolong the service life of road surface. Especially, the requirement for asphalt binder is increasing due to the development of asphalt pavement technology.
In order to improve usability of asphalt and achieve quality level of engineering requirements, various modified asphalts prepared by methods such as blending and adding admixture, etc, are employed to meet engineering requirements. Although the generalization of modified asphalts improves pavement performance, the thermoplasticity of the asphalt is not changed, therefore, it is difficult to overcome common defects of asphalt pavement.
Thermoset-modified asphalt mixture is prepared from thermosetting resin and graded aggregates. The thermosetting resin includes epoxy resin, polyurethane, phenolic resin, polyester and the like. During modification process, the thermosetting resin is reacted with curing agent in a curing reaction to form an irreversible cured substance which is crosslinked in is network structure. The curing reaction converts thermoplastic asphalt into thermoset asphalt; therefore, the thermoset-modified asphalt has excellent physical and mechanical performances. Generally, the thermoset-modified asphalt mixture is constituted by adding certain stone materials. Due to the fact that the thermosetting resin possesses high strength after curing, it is also called high-strength asphaltic concrete material. The thermosetting resin, which has large rigidity, good flexibility, excellent fatigue resistance and durability, is an ideal material for pavement layer of steel bridge deck, pavement wearing layer and overload traffic road, and has wide application prospect.
At present, the most widely-used material in thermoset modification technology is epoxy asphalt mixture. A conventional modification technology for epoxy asphalt mixture is wet modification technology, comprising firstly preparing epoxy-modified asphalt which generally comprises two components, wherein the first component is epoxy resin and the second component comprises asphalt and other components such as curing agent, etc., the two components are mixed at a certain ratio to form epoxy resin-modified asphalt; and then adding some stone materials into the epoxy-modified asphalt to produce the epoxy asphalt mixture. Such method not only requires complex process, but also generally has difficulty in forming stable modified asphalt when epoxy resin and curing agent are directly added into the asphalt, due to the incompatibility of asphalt and epoxy resin with each other.
Chinese Patent CN101255276A discloses an epoxy asphalt material for road-bridge and the environment-friendly preparation method thereof. Asphalt is modified in the method by grafting reactive functional groups onto the asphalt to improve the compatibility between epoxy resin and asphalt and make asphalt itself become a curing agent for epoxy resin, forming a composite curing agent by combing asphalt with a curing agent and a promoter, and mixing the composite curing agent with epoxy resin to prepare the modified asphalt. Chinese Patent CN1952012A discloses a thermosetting epoxy asphalt material prepared by utilizing a special compatibilizer to improve the compatibility between epoxy resin and asphalt. The method for preparation of the compatibilizer is complex method with a high cost, and is not suitable for use in industry. Furthermore, it is difficult to control the stability of modified asphalt in practical application, thereby making the application complex.